氢氟酸腐蚀对α-Fe_2O_3薄膜光解水电极光电化学性质的影响（英文）  

Effect of HF Treatment on the Photoelectrochemical Properties of a Hematite Thin Film Photoanode for Water Splitting

作　　者：胡玉祥[1] 姜春香[1] 方亮[1] 郑分刚[1] 董雯[1] 苏晓东[1] 沈明荣[1] 

机构地区：[1]苏州大学物理与光电.能源学部,江苏省重点薄膜实验室,江苏苏州215006

出　　处：《物理化学学报》2014年第6期1099-1106,共8页Acta Physico-Chimica Sinica

基　　金：supported by the National Natural Science Foundation of China(91233109);Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China~~

摘　　要：使用溶胶-凝胶法制备了α-Fe2O3薄膜,研究了氢氟酸腐蚀薄膜表面对其光电化学性质的影响.实验发现,薄膜表面的孔洞和间隙随着氢氟酸浸蚀时间的增长而发生变化.氢氟酸浸蚀5 min,α-Fe2O3电极的光电流降低;随后随浸蚀时间增加而迅速增加;当浸蚀时间大于15 min时,其光电流再次下降,但对浸蚀过的样品再次退火可以使光电流大幅增加.通过电化学交流阻抗谱、拉曼和X射线光电子能谱分析,提出了两个影响光电流的因素:氢氟酸表面浸蚀造成薄膜表面的多孔性和结晶度降低.为此,通过示意图解释了结合浸蚀和退火后处理两个步骤来增强α-Fe2O3薄膜光解水电极光电活性的原理.相对于初始的α-Fe2O3电极,浸蚀并且再退火处理后,其光电性质更加稳定.The effects of HF treatment on the photoelectrochemical （PEC） properties of sol-gel prepared hematite （α-Fe2O3） thin films were investigated. Pores and interstices between the grains developed on the film surface as the HF etching time increased. The photocurrent density of theα-Fe2O3 photoanode decreased within the first 5 min of etching, and then increased quickly as the etching time increased. At longer time than 15 min the photocurrent density deteriorated. Re-annealing the etched samples significantly enhanced the photocurrent density. Based on electrochemical impedance spectroscopy, Raman and X-ray photoelectron spectroscopies, we propose that two factors contribute to photocurrent density reversely： the porosity and the lowered crystal inity of theα-Fe2O3 surface because of HF treatment. A schematic model was compiled to explain the enhanced PEC activities of the etched plus re-annealedα-Fe2O3 photoanode. The PEC and water splitting measurements showed that the etched plus re-annealed photoanode is more stable than the as-prepared one.

关 键 词：α-Fe2O3光电极 表面处理 光电化学性质 

分 类 号：O646.54[理学—物理化学]